Would you consider your cervix a close friend or more of a casual acquaintance? It's been there the whole time, but how often are you really getting up there to say hello? If you're thinking, Literally never, don't stress. The truth is that far too many of us simply aren't tuned into the cool things our cervixes are doing throughout the month, every month, right below our belts.

"The cervix is the area of tissue that marks the mouth of the uterus," says Taraneh Shirazian, MD, assistant professor of obstetrics and gynecology at NYU Langone Medical Center. Essentially, it functions as the entrance from the vaginal canal into the uterus, where sperm have to travel to meet an egg.

So this humble barrier actually has a huge job — it's the gateway between pregnancy and non-pregnancy — and it's one we should probably all be paying a little more attention to. (Partly because it's just plain fascinating.) Continue on to learn what your cervix does, how it changes, and how you can keep it healthy and happy.